Types of Pathogens

Bacteria

prokaryotic unicellular organisms that may contain either DNA or RNA, thrive as autotrophs, saprophytes, or parasites, often live in soil, water, organic matter, or in plants and animals

Structural Groups of Bacteria - Spherical

cocci

Structural Groups of Bacteria - Oval/Rod

bacilli

Structural Groups of Bacteria - Spiral

spirilla

Divisional Groups of Spherical Bacteria - Groups of Two

diplococci

Divisional Groups of Spherical Bacteria - Chains

streptococci

Divisional Groups of Spherical Bacteria - Grape-like Bunches

staphylococci

Bacterial Spores

protective coat surrounding nucleic material of some bacteria

Examples of Bacterial Infections - Tuberculosis

caused by acid-fast aerobic Mycobacterium species

Examples of Bacterial Infections - Bacterial Pneumonia

transmitted through a tick bite infected with Borrelia bacterium

Examples of Bacterial Infections - Lyme Disease

caused by Borrelia bacteria

Examples of Bacterial Infections - Gonorrhea

sexually transmitted infection affecting both males and females

Fungi

eukaryotic organisms that thrive as saprophytes or parasites, exist in two forms: yeasts and molds

Yeasts

unicellular fungi

Molds

multicellular fungi

Fungal Reproduction

reproduce by budding or spore formation

Fungal Infections

occur in warm, moist areas such as scalp, feet, and groin

Examples of Fungal Infections

athlete's foot, ringworm, candidiasis, vulvovaginitis

Viruses

simple microorganisms consisting of a protein coat surrounding either DNA or RNA, requiring a host cell for reproduction

Examples of Viral Infections

HIV, mumps, influenza

Prions

abnormal protein particles capable of replicating in mammalian cells, lacking DNA or RNA

Examples of Prion Infections

spongiform encephalopathies, Creutzfeldt-Jakob disease, kuru

Parasites

organisms that live on or in other organisms at the host’s expense

Protozoa

complex unicellular microorganisms, thrive as heterotrophs, often parasitic

Protozoan Motility - Pseudopod Formation

amoeboid movement where one part of the cell moves forward and the rest follows

Protozoan Motility - Flagella

whip-like projections for movement

Protozoan Motility - Cilia

hair-like projections on the exterior of the cell wall

Examples of Protozoan Infections

amoebiasis